1-para-dimethylaminophenyl-2. 3. 4-trimethyl-5-pyrazolone and process of making same.



"entrain ss smnnmcn sronz AND enonc ironunonrnn, or HocHsn'omrHn-Mnir, QER ANY,

assrcnons r0 \FARBWERKE voam. MEISTER LUCIUS a BRUNING, or HOCHST-ON- THE-MAIN, GERMANY.

It-PAIRADIMETHYLAMINOPHENYL-2. 4.-TBIMETHYL-5-PYRAZOLONE AND PROCESS OF MAKING SAME.

scenic.

2E0 Brewing Specification of Letters Patent.

. Application fil ed June 14, 1910. Serial No. 566,818.

Patented Apr. 25, 1911.

the structural formula 1.4. cannons oe NGH,

cn,-d=d-on,.

This new compound is of great therapeutical Value; it is favorably distinguished from the 1-para-dimthylaminophenyl-Q. 3- diinethyl-o-pyrazolone by being much less poisonous without its efficacy being thereby diminished. It could-not be foreseen that the said result would be obtained by the introduction of a methyl group, because, for instance tolypyrin and methylantipyrinare more poisonous than antipyrin, Whereas the new methylated compound dpossesses the opposite property as compare with the parent product.

reaction is dissolved in water, the solution oVersat-urated with alkali and the methylated base shaken outwith benzene or some other suitable solvent. The product left after the it from ethyl-acetate or alcohol.

The para dimethylaminophenyh trimethyl pyrazolone crystallizes from water With water of crystallization. /Vhen well dried the compound melts at about 140; it is pretty readily soluble in Water, readily soluble in dilute acids, alcohol, benzene, and

chloroform; its aqueous solution, when treated with ferric chlorid, assumes a red coloration; no reaction occurs in presence of nitrous acid. h

The aforesaid 1-para'a1ninophenyl-2. 3. 4- trimethyl-5-pyrazolone can be produced from para-nitrophenyl-2. 3. 4c-trimethyl-5- pyrazolone, described in U. S. Patent No. 936,380, by reduction with tin and hydro chloric acid. On supersaturating with caustic soda lye, the l-para-aminophenyl-Q. 3. 4- trirnethyl-5-pyrazolone separates from the hydrochloric solution, after being freed from benzene has been distilled ofl' can'be purified by dissolving it in water and recrystallizing the tin and evaporated, asia white crystalline powder. The base thus obtained crystallizes from hot Water in the form of colorless crystals containing two molecules of water of crystallization; when free from water, it melts at 225227.

I Having now particularly described our invention, what we claim is:

1.v The process of manufacturing l-paradimethylaminophenyl-Q. 3. 4-tri1nethyl-5- pyrazolone, which consists in methylating .l para aminophenyl 2. i 3. 4 trimethyl-S- pyrazolone. v

2. As a new product, l-para-dimethylaminophenyl-2. 3. l-trimethyl-fii-pyrazolone, being a White, well crystallizing powder melting at about 140, readily soluble in dilute acids, alcohol, benzene and chloroform, pretty readily soluble in water, and

yielding, when dissolved in water with ferric chlorid, a red solution.

. In testimony whereof, We 7llllX our signatures in presence oftwo witnesses.

FRIEDRICH STOLZ. GEORG KORNDORFER. Witnesses:

JEAN GRUND, CARL GRUND. 

